Cable staple



April 1932- s. N. BUCHANAN ,3

C ABLE STAPLE Filed Dec. 17, 1928 ill... IWI EW- MHHHL HHH awuemtoz STEPHEN N. MAMA Patented Apr, 26, 1932 V UNITED STATES PATENT OFFICE- STEPHEN N. BUCHANAN, or ELIZABETH, Nriw'iEnsEY, ASSIGNOR mo THE 'rnoigAs & ZBETTS 00., or ELIZABETH, NEW JERSEY. A CORPORATION or NEW JERSEY CABLE s'rArLE This invention relates to cable staples for use m connection with nailing down and anchoring electrical cable conduits and the like to the frame or other structural parts of the building in connection with the installation of electrical wiring systems. A

An object of the invention is to produce a cable staple which will securely hold the cable in place and which will not tend to spread or open the seams of the spirallywrapped metal armored cable; and it is also an object to produce a staple which will positively hold the cable against longitudinal displacement from its anchored position.

In the accompanying drawings, there are illustrated examples of the improved cable staple and it is understood that certain changes in structure may be resorted to withelevation with the staple in section.

Figure 4 shows a plan view of a cable with the staple engaging'the same, and Figure 5 shows a similar view, in plan section.

Figure 6 shows a modified form of the cable staple wherein one prong or leg thereof is made longer than the other so as to secure a deeper and stronger hold in a timber or frame which might not withstand the driv- 111 force of two long staple legs or prongs. igure 7 shows a'strip of metal suitably marked off for the manufacture of the staples and illustrates the manner in which the staples are struck or stamped from a single sheet metal strip.

Figure 8 shows prongs to complete the staple.

Figure 9 isa perspective view of'tli'e completed staple.

The cable staple is'so designed and constructed that it spreads across the folds, corprongs hence anchors the cable ag the stamped blank in flat formation before bending down the legs or -er. prong rugations or convolutions of a spirallywrapped armored electrical cable in such a way that the driving of the staple prongs into the wood or frame on which-the cable is mounted does not spread or damage the cable and this is attained by forming on a bias the diagonally'opposite edges defining the staple legs which results in forming a staple the combined width of whiclnis wider from edge to edge, longitudinally of .the cable, than the distance between the convolutions.

- Accordingly, a staple has its head 10 integrally formed with legs or prongs 11 and 12 and the staple is formed by making its edges 13 and 14: parallel and by making its other edges 15 and 16 at an angle and biased to the parallel edges 13 and 14. The angular edges 15 and 16 are formed diagonally opposite each other while the parallel edges 13 and 14 are similarly formed opposite each other but are parallel. Furthermore the biased angular edges 15 and 16 are preferably shorter than the parallel edges 13 and 14 which avoids cuttin into and reducing the width of the staple ead 10. y

The head 10 of the staple may be formed flat as shown and includes a boss 18 struck downwardlyo towards the points of the staple or points. The boss 18 fits into the corrugation C left between the folds or spirally wrapped ribbon forming the cable and ainst longitudinal motion after the staple is driven into the wooden member to which the cable is adapted to be anchored.

Figure 6 shows a. modified form of the cable staple wherein one leg or pointed prong is longer 10 and cable anchorage boss 18 may be formed similar to'the staple already described. This is attained by making one biased angular edge 15a longer than the other biased angular edge 16a. Hence one prong 20 is longer than the other prong 21 and the longmore effectively drives into a a wooden timber of the building without splitting the wooden piece than is always possible to do in the'case of a staple having two long prongs.

In the manufacture of the cable staple a than the other leg 21 but the head a single sheet or strip of metal as shown in Figure 7 is struck oflt along the angular disposed lines 15 and 16 which provides biased leg edges as already described and also forms sharp points on the extremities of the legs of the staple so that it may be driven easily into a wooden timber. I

It is significant that the combined parallel and biased edge formation so forms the staple legs that they are diverted at right angles from the head 10 and drive into the wooden sill or support with ease because the prongs are sharp and slender. F urthermore the diverging prongs tend to increase the general overall width, longitudinally of the staple. This improved cable staple fills a want long felt for a positive anchorage cable staple which will hold but not damage the cable. p It is seen that this staple cannot be driven down into the grooves of the cable because it has a wide head and its legs are disposed at an'angle to a line perpendicular to the axis of the cable andhence cross the grooves. 2 In other words the legs of this staple always overlap, cross or straddle the grooves of the cable and the cable cannot be spread open. Furthermore the legs. of the staple tend to increase their angular relation as the staple is driven into the wooden member and this is brought about by the action of the diagonally opposite edges 15 and 16 which tends to spreadthe legs at an increasingly greater angle as the staple is driven into the wooden part. Hence the staple holds its anchorage in a very secure manner.

It is also seen that the staple head 10 is fiat instead of arched or round and the flat head drives the pointed legs into the wood in 4 a more satisfactory way. When the hammer blow strikes the head 10, the latter being fiat does not flatten out and hence there is no tendenc' to spread and loosen the staple about the ca le. 46 What is claimed is:

A unitary cable staple for anchoring spirally indented electrical cable conduits comprising a bridging head anddiverging leg I portions, the said head having a suflicient 50 width to overlap adjacent convolutions of the conduit on which it is used and having a boss portion projecting inwardly from the said head portion for engaging a spirally indented portion of the said cable conduit to positively hold the cable conduit against longitudinal displacement.

In testimony whereof I aflix my signature.

STEPHEN N. BUCHANAN. 

